The present invention pertains generally to polymer blend compositions which comprise a rubber modified monovinylidene aromatic polymer in combination with particular proportions of certain selected elastomeric thermoplastic polyurethane ingredients and which are particularly well suited for use in various extrusion compounding, injection molding, blow molding and sheet extrusion/thermoforming end-use applications
The general concept of blending urethane polymers and butadiene rubber modified styrene acrylonitrile (ABS) polymers is disclosed in U.S. Pat. No. 3,049,505. Other U.S. Patents which deal generally with the subject of blends of polyurethane materials with thermoplastic polymer ingredients such as ABS resins include U.S. Pat. No. 4,317,890 which is concerned with blends comprising from 75 to 97 weight percent of a thermoplastic polyurethane in combination with from 3 to 25 weight percent of a relatively lightly grafted graft copolymer and U.S. Pat. No. 4,342,847 which is directed to a method for producing blends of thermoplastic polyurethanes with other thermoplastic materials by way of an in-situ polymerization/blending process wherein from 35 to 96 parts by weight of the polyurethane ingredient is polymerized in an extruder and in the presence of from 4 to 65 parts by weight of a previously formed thermoplastic polymer ingredient. U.S. Pat. No. 4,179,479 to Carter is also concerned with thermoplastic polyurethane compositions optionally containing as much as about 60 weight percent of various other thermoplastic polymer ingredients such as emulsion polymerized ABS compositions, polyoxymethylenes, polycarbonate, etc.
Additional references dealing with the subject of polymer blend compositions containing rubber modified thermoplastics such as ABS resins in combination with various urethane polymer ingredients include published Japanese patent application numbers J51-126,245-A J60-067,219-A and J61-152,760-A.